Shaft furnace charging device



Ap 6, 1954 E. T. A. TESCH ETAL SHAFT FURNACE CHARGING DEVICE 3Sheets-Sheet 1 Filed May 24, 1950 INVENTORS Erik Torsten Anderson Tesch8 Isak Edwin Johonsson ATTORNEYS Apr 6, 1954 E. 1-. A. TESCH ETAL SHAFTFURNACE CHARGING DEVICE 3 Sheets-Sheet 2 Filed May 24, 1950 INVENTORSErik Torsten Andefson Tesch 8: Isak Edvin Johmnsson ATTORNE S v BY April6, 1954 E. T. A. TESCH ETAL SHAFT FURNACE CHARGING DEVICE 3 Sheets$heet3 Filed May 24, 1950 INVENTORS son Tesch Erik Torsien Ander ATTORNEYSPatented Apr. 6, 1954 SHAFT FURNACE CHARGING DEVICE Erik TorstenAnderson 'ilesch, Stockholm, and Isak Edvin Johansson, Alvsjo, SwedenApplication May 24, 1950, Serial No. 164,012

Claims priority, application Sweden June 1, 1949 2 Claims.

pass through a cone when falling into the shaft furnace, which is nowusually practiced, does not result in the desired distribution, interowing to the tendency of the material to separate according to size andspecific gravity. The rising gases follow the law of least resistanceand thus they flow more amply where coarser material is concentrated andthe charge is looser than where there is finer material and the chargeis correspondingly tighter. This will cause uneven reduction of the orein the material and the useful volume of the furnace will be lesseffectively utilized. Moreover, the departing gas will be tooununiformly composed causing a reduction of heat economy. Disturbancesin operation may also result on account of the gas forming irregu- 1 larpassages in the material.

One way of obtaining a more uniform gas flow in the furnace is to chargea comparatively large quantity of small size material concentricallyaround the wall of the furnace, so called charge on the wall, and acomparatively smaller quantity of coarser material in the central partof the furnace, so called charge in the centre.

A disadvantage with such charging tops, however, is that chargingrequires expensive manual labour for loading and separating thesmallpiece material and further they can not be designed for doubleclosure, which allows the gas to escape through the top, while thematerial is being introduced into the furnace.

In order to obtain a better distribution of the material it has alsobeen suggested to close the opening of the cone-shaped bottom of thecharging top by means of a conical valve which,

in order to empty the charging top, may either be raised above itsclosing position, when the material is to fall into the centre of thefurnace, or be lowered below said position, when the ma terial is tofall outwardly towards the furnace wall.

Also this device, however, has disadvantages in as much as the height offall of the material is changed, when the conical valve is moved from aposition above the opening in the bottom To prevent such a change in theheight of fall of the material in operating the conical valve, thebottom closure of the charging top according to the present inventioncomprises two conical valve members arranged one below the other andeach being adapted to be raised and lowered, at least the lower one ofsaid valve members being smaller than the opening in the bottom of thecharging top, so that said lower valve not only can be raised above saidopening together with the upper one in order to effect a central chargebut also independently of the upper valve can be lowered below theopening in order to allow charge on the wall.

When material is to be fed to the centre of the shaft furnace bothvalves are raised together, whereas when the material is to be fedaround the wall of the furnace, the lower valve is first lowered to itslowermost position, whereupon the upper valve is raised to its uppermostposition. Thus the material during the whole charge will fall from aconstant height against the lower valve and will slide along the conicalsurface of the latter out towards the wall of the shaft furnace.Preferably the upper valve is so shaped that it is somewhat larger thanthe opening in the bottom of the charging top, thus ensuring a gas-tightseal when the valve is in its lowered position.

In order to further ensure feeding of the material towards the wall theupper part of the furnace, according to one embodiment of the invention,may be provided with a fixed conical guide-casing having a centralpassageway, the lower conical valve cooperating with said casing whenlowered to a position below the opening in the bottom of the chargingtop, said casing also being arranged so as to allow the material to fallthrough the central passageway of the casing when the lower valve is inits raised position.

This device ensures a very favourable distributicn of the material inthe furnace.

According to another embodiment of the invention the conicalguide-casing and maybe also the lower conical valve is provided with anumber of radial ridges or grooves which ensure a radial andcircumierentially equal flow of material towards the wall of thefurnace.

Experience has proved that material sliding down along a smooth conedoes not always move radially outwards. Often, especially when handlingmaterial comprising pieces of different sizes, this sliding motion willbe irregular and in of the charging top to a position below the same. 55

places may diverge in tangential direction so that the material will notbe passed down evenly distributed as desired.

By providing the distributor with radial guide ridges the material isprevented from diverging in tangential direction, but is guided ingrooves radially outwards so that the charge will be en tirely uniformaround the circumference of the furnace where the risk of anuncontrolled passage of gas is the greatest.

Further, the conical casing according to the invention may be extendeddownwards from its outer periphery with a cylindrical or nearlycylindrical part adapted to guide the material of the chargeconcentrically along the furnace wall.

Other features of the invention willbe further indicated in thefollowing description referring to the shaft furnace illustrated in theaccompanying drawings, in which:

Fig. 1 is a vertical section through the furnace and charging top, whileFig. 2 illustrates a part thereof. Figs. 3 and 4 show the charging topand adjacent parts of the furnace on a somewhat larger scale and in twodifferent positions of operation.

The shaft furnace is designated A, the lower container of the doublecharging top is designated B and its upper container C. The latter ispreferably rotatably mounted on rollers 2. The material is supplied tothe furnace by the selftilting wagon l. After a suflicient quantity ofmaterial has been supplied to the container ,0, the conical valve 3 islowered by means of the compressed air cylinder 4, the lever 5 with itscounter-weight 6 and the hollow supporting rod 1. The charge materialwill thus slide down from the container C to the container B, whereuponthe container C is closed by the valve 3 again being raised against theconically shaped bottom 8 of the container.

After this the material is expelled from the container B intothe shaftfurnace A either by raising *both conical valves 9 and 25 according toFig. 3, thus allowing the material to fall down into the centre of thefurnace, or by lowering the valve 25 and raising the valve 9 accordingto Fig. 4, causing the material to slide down around the wall 2! of thefurnace A. In order to protect the wall against wear thereis a liningIS.

The distributor l4, which is fixed in the upper part of the furnace isadapted to guide the material out against the wall 2!, as shown in Fig.4. The valve member 25 and the distributor l4 carry members i? on theupward surfaces thereof forming radially extending ribs for guiding thestock flow thereover. A cylindrical member 15 is provided interiorly ofthe upper portion of the furnace wall 2| adjacent to the distributor I 4in order to provide a wear resistant surface upon which the stock.flowing outwardly over the distributor may impinge. In the embodimentillustrated in the drawing the distributor I4 is extended downwardlywith a cylindrical part l8 so that an annular space I9 is formed forguiding the charge.

Fig. 2 shows in detail firstly how the valve 9 tightly engages thebottom 16 of the container, secondly how the valve 25 fits into thevalve" 9 and thirdly that the valve 25 may unimpededly be loweredthrough the opening in the bottom i6 of the container B.

In the shown embodiment the valve 9 is operated by the compressed aircontainer H], the lever H with its counter-weight l2 and the hollow rodl3. The valve 25 is operated by the compressed air container 25, thelever 21 with 4 its counter-weight 28 and rod 29. The gas outlets fromthe furnace are designated 22. 23 is a safety valve.

Naturally the valves may also be operated by some other means, forinstance hydraulically, by means of electrically driven hoists, etc., ormanually.

Having now particularly described the nature of our invention and themanner of its operation what we claim is:

1. A charging device for a shaft furnace comprising a charging top and astationary conical guide having a central opening therein affixed to theupper part of the furnace below the charging top and independently ofthe charging top, said charging top including a bottom portion in theform of an inverted cone having an opening in the bottom thereof, aclosure for said charging top opening including an upper conical valvemember, and a lower conical valve member arranged below the upperconical valve member, said valve members being adapted to be raised andlowered independently of each other, the upper valve member being oflarger diameter than the opening in the charging top and being adaptedto seal the opening when in engagement with the rim thereof, and thelower valve member being of smaller diameter than the opening in thebottom of the charging top so that, when the upper valve member israised above said opening, said lower valve member can be selectivelyraised above said opening or lowered below said opening independently ofsaid upper valve member, said lower valve member being of smallerdiameter than the opening in the stationary conical guide, said lowervalve memher and said stationary conical guide both including aplurality of radially extending guide ribs on their upper surfaces forguiding material in flow thereover and said stationary guide including acylindrical extension projecting downwardly from its outer periphery,the diameter of the cylindrical extension of the stationary guide beingsubstantially greater than the diameter of the central opening in thestationary guide, a cylindrical member mounted on the interior surfaceof the upper end of the furnace Wall adjacent to the cylindricalextension of said stationary conical guide, said stationary conicalguide and cylindrical extension forming the inner wall and saidcylindrical member forming the outer wall of an annular space within theupper part of the furnace, said conical guide being so positioned thatsaid lower valve memher, when lowered to a position below the opening inthe bottom of the charging top and to the level of the top of theconical guide, coopcrates with the conical guide for feeding materialdown through the annular space around the conical guide, and said lowervalve member, when raised to a position above the opening in the bottomof the charging top, cooperates with the bottom of the charging top forfeeding material through the central passageway in the conical guide.

2. A charging device for a shaft furnace comprising a charging top and astationary conical guide having a central opening therein aflixed to theupper part of the furnace below the charging top and independently ofthe charging top, said charging top including a bottom portion in theform of an inverted cone having an opening in the bottom thereof, aclosure for said charging top opening including an upper conical valvemember. and a lower conical valve member arranged below the upperconical valve member, said valve members being adapted to be raised andlowered independently of each other, the upper valve member being oflarger diameter than the opening in the charging top and being adaptedto seal the opening when in engagement with the rim thereof, and thelower valve member being of smaller diameter than the opening in thebottom of the charging top so that, when the upper valve member israised above said opening, said lower valve member can be selectivelyraised above said opening or lowered below said opening independently ofsaid upper valve member, said lower valve member being of smallerdiameter than the opening in the stationary conical guide, said lowervalve member and said stationary conical guide both including aplurality of radially extending guide ribs on their upper surfaces forguiding material in flow thereover and said stationary guide including acylindrical extension projecting downwardly from its outer periphery,the diameter of the cylindrical extension of the stationary guide beingapproximately twice the diameter of the central opening in thestationary guide, a cylindrical member mounted on the interior surfaceof the upper end of the furnace wall adjacent to the cylindricalextension of said stationary conical guide, said stationary conicalguide and cylindrical extension forming the inner wall and saidcylindrical member forming the outer wall of an annular space within theupper part of the furnace, said conical guide being so positioned thatsaid lower valve member, when lowered to a position below the opening inthe bottom of the charging top and to the level of the top of theconical guide, cooperates with the conical guide for feeding materialdown through the annular space around the conical guide, and said lowervalve member, when raised to a position above the opening in the bottomof the charging top, cooperates with the bottom of the charging top forfeeding material through the central passageway in the conical guide.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 809,754 Shackleford Jan. 9, 1906 864,053 Witherbee et a1. Aug.20, 1907 967,328 Collord Aug. 16, 1910 1,333,957 Bird Mar. 16, 1920

